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Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Adaptive Reference Levels in a Level-Crossing Analog-to-Digital Converter | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 513706 11 pages doi 10.1155 2008 513706 Research Article Adaptive Reference Levels in a Level-Crossing Analog-to-Digital Converter Karen M. Guan 1 Suleyman S. Kozat 2 and Andrew C. Singer1 1 Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Urbana IL 60801 USA 2 Department of Computer Engineering College of Engineering Koc University 34450 Istanbul Turkey Correspondence should be addressed to Andrew C. Singer acsinger@uiuc.edu Received 24 October 2007 Revised 30 March 2008 Accepted 30 June 2008 Recommended by Sergios Theodoridis Level-crossing analog-to-digital converters LC ADCs have been considered in the literature and have been shown to efficiently sample certain classes of signals. One important aspect of their implementation is the placement of reference levels in the converter. The levels need to be appropriately located within the input dynamic range in order to obtain samples efficiently. In this paper we study optimization of the performance of such an LC ADC by providing several sequential algorithms that adaptively update the ADC reference levels. The accompanying performance analysis and simulation results show that as the signal length grows the performance of the sequential algorithms asymptotically approaches that of the best choice that could only have been chosen in hindsight within a family of possible schemes. Copyright 2008 Karen M. Guan et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Level-crossing LC sampling has been proposed as an alternative to the traditional uniform sampling method 110 . In this approach signals are compared with a set of reference levels and samples taken on the time axis indicating the times .
